Load arrangement and electrical power arrangement for powering a load

ABSTRACT

The present invention relates to a load arrangement (400) for use in an electrical power arrangement (200) and for getting arranged at a first external electrically conductive element (50). The load arrangement comprises a load (20) having a first load terminal (2a) and a second load terminal (2b) for being powered by an AC power source (1), a first electrode (3) electrically connected to the first load terminal (2a), and a dielectric layer (4). The first electrode (3) and the dielectric layer (4) are arranged to form, in combination with a first external electrically conductive element (50) representing an outer surface of a marine structure, a capacitor (6) for capacitive transmission of electrical power between the first electrode (3) and the first external element (50). At least one of the capacitor (6) and the second load terminal (2b) is arranged for electrical power transmission through water (10) to form an electrical path via the water (10) between the AC power source (1) and the respective one of the capacitor and the second load terminal (2b). The first load terminal (2a) is electrically insulated from the second load terminal (2b).

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is the U.S. National Phase application under 35 U.S.C.§ 371 of International Application No. PCT/EP2016/082363, filed on 22Dec. 2016, which claims the benefit of European Patent Application No.15202429.5, filed on 23 Dec. 2015. These applications are herebyincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to a load arrangement for use in anelectrical power arrangement and for getting arranged at a firstexternal electrically conductive element. The present invention relatesfurther to an electrical power arrangement for powering a load of such aload arrangement.

BACKGROUND OF THE INVENTION

WO 2009/153715 A2 discloses a light emitting device comprising a firstcommon electrode, a structured conducting layer, forming a set ofelectrode pads electrically isolated from each other, a dielectriclayer, interposed between the first common electrode layer and thestructured conducting layer, a second common electrode, and a pluralityof light emitting elements. Each light emitting element is electricallyconnected between one of the electrode pads and the second commonelectrode, so as to be connected in series with a capacitor comprisingone of the electrode pads, the dielectric layer, and the first commonelectrode. When an alternating voltage is applied between the first andsecond common electrodes, the light emitting elements will be poweredthrough a capacitive coupling, also providing current limitation. Duringoperation of the light emitting device, a short-circuit failure in onelight emitting element will affect only light emitting elementsconnected to the same capacitor. Further, the short-circuit current willbe limited by this capacitor.

In certain application scenarios such a light emitting device, inparticular the way of powering the light emitting device (or generally aload), has disadvantages, e.g. due to the electrical connection betweenthe common electrode layer and the AC voltage source. Such applicationscenarios include, for instance, systems for anti-fouling of a surface(e.g. a ship hull) while said surface is at least partially submersed inan liquid environment (e.g. sea water), in which UV light is emitted bylight sources mounted in some way to the outer surface of the ship hullto counter bio-fouling of the ship hull.

WO 2014/060921 A1 discloses an LED package arranged to emit light whenconnected to an AC power supply, comprising a first and a second LEDpackage terminal, at least one pair of diodes connected in anti-parallelbetween the LED package terminals, wherein at least one of the diodes isa light emitting diode. The first LED package terminal is detachablyconnectable to a first power supply terminal, and adapted to form afirst capacitive coupling together with the first power supply terminal,and the second LED package terminal is detachably connectable to asecond power supply terminal, and adapted to form a second capacitivecoupling together with the second power supply terminal. By providingelectrical connections which are less sensitive to temperature dependentdegradation, the life time of the LED package may be increased.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved loadarrangement and an improved electrical power arrangement for powering aload, which can be used in particular application scenarios under moredifficult environmental conditions with little or even no loss ofperformance and without the risk of getting damaged, e.g. due toexposure to environmental influences, such as exposure to sea water.

In a first aspect of the present invention a load arrangement ispresented comprising

a load having a first load terminal and a second load terminal for beingpowered by an AC power source,

a first electrode electrically connected to the first load terminal, and

a dielectric layer,

wherein the first electrode and the dielectric layer are arranged toform, in combination with a first external electrically conductiveelement representing an outer surface of a marine structure, a capacitorfor capacitive transmission of electrical power between the firstelectrode and the first external element,wherein either the capacitor and the second load terminal is arrangedfor electrical power transmission through water to form an electricalpath via the water between the AC power source and the capacitor, and/orthe second load terminal is arranged for electrical power transmissionthrough water to form an electrical path via the water between the ACpower source and the second load terminal, andwherein the first load terminal is electrically insulated from thesecond load terminal.

In a further aspect of the present invention an electrical powerarrangement is presented comprising

an AC power source and

a load arrangement as disclosed herein.

Preferred embodiments of the invention are defined in the dependentclaims. It shall be understood that the claimed electrical powerarrangement has similar and/or identical preferred embodiments as theclaimed load arrangement, in particular as defined in the dependentclaims and as disclosed herein.

The present invention is based on the idea to modify and optimize theuse of capacitive power transfer for application in a challenging wetenvironment, in particular the conductive and harsh ambient environmentof the sea. Furthermore, the electric circuit of the load arrangementand of the electrical power arrangement has been adapted for robustnessagainst moderate and severe impact as well as surface cutting damage atvarious levels, such as for example UV-C LEDs (as loads) developing oneor more open or short-circuit connections. This is achieved by makinguse of a first external electrically conductive element, which forms acapacitor together with the first electrode and the dielectric layer forcapacitive transmission of electrical power between the first electrodeand the first external element. The electrical power may thereby beprovided by an AC power source, whose first AC terminal is electricallyconnected to the first external element providing a clearly definedvoltage potential at the first external element when the electricalpower arrangement is in use.

Further, the water is used to transfer electrical power between the ACpower source and either the capacitor and/or the second load terminal,i.e. an electrical path is formed through the water. Thus, the galvanicconnections can be avoided, but the water is efficiently used instead,which also makes installation of load arrangements at a marinestructure, e.g. a ship hull, easier and cheaper, for instance if theload arrangements are configured in the form or stickers or plates.

According to the arrangement disclosed in WO 2009/153715 A2 a rigidcarrier is deployed to carry electronic components such as for exampleLEDs. A disadvantage of this carrier is that it is only bendable to someextent, yet, even than it will be difficult to apply such carriers tothree dimensional curved surfaces, such as the surfaces of a ship hull.Furthermore, although such carriers may be built segmented to yield moreflexibility, the freedom of placement of such carriers is limited. Tothat end, the carrier is preferably broken or cut into individualsubcarriers, thereby disrupting the common power supply terminal. Incontrast, according to the present disclosure a sticker likearrangement, e.g. placed on a carrier, is chosen to cope i) withcontoured surfaces and ii) to allow for full freedom of (partiallyoverlapping) placement, while still ensuring a common power supplyterminal by means of using of a common liquid conductor, such as wateror sea water. Furthermore, it is desirable that only submerged loads areoperated, for example for safety and energy efficiency. Since the waterlevel along the hull self-adapts to the varying sailing speeds of theship, the weather conditions at sea and the cargo loading conditions ofthe ship, it may be clear that also the common power supply terminaladapts instantaneously without the need for controlling electronics.

In an embodiment the first external electrically conductive element isselected from the group of electrically conductive elements comprisingwater, in particular sea water, an environmental object, in particular apart of a building or vehicle, and an infrastructural object. Thus, theload environment can generally be used in various applications. Forinstance, the first external element may be a ship hull, to which aplurality of load arrangements (e.g. each comprising one or moreUV-LEDs) are mounted to counter bio-fouling. The ship hull can thus befavorably used as one electrode of the first capacitor and thus avoidsproviding galvanic connections between a first AC terminal of the ACpower source and a first load terminal of the load (the one or moreUV-LEDs), i.e. the ship hull needs not to be pierced to provide suchgalvanic connections and thus leads to a better construction and lessdeterioration of the ship hull.

Preferably, the first external electrically conductive element is amarine structure, the second load terminal has an electrical connectionto water to form an electrical path via the water between the AC powersource and the second load terminal, and the AC power source is attachedto the marine structure and the AC power source has an electricalconnection to water to complete the electrical path via the waterbetween the AC power source and the second load terminal. Thus, thewater is efficiently used as electrical conductor.

In other embodiments the first external element is a ship hull or anelectrode embedded or connected to a non-conductive marine structure.

The second load terminal and the AC power source may have a capacitiveelectrical connection to water or a resistive electrical connection towater. Resistive is a direct electric connection between the secondelectric terminal of the AC generator (the power output side) and theseawater, by means of a water submersed electrode. Because sea water isquite aggressive these electrodes are very expensive and often consistof MMOTi (mixed metal oxide-coated titanium) or PtTi (platinum coatedtitanium). Because ICAF (impressed current antifouling) or ICCP(impressed current cathodic protection) systems already deploy suchelectrodes, the AC generator used in the disclosed system can co-utilizethis electrode, i.e. the electrode comes for free. In the case of acapacitive electrical connection the aggressive action of the seawateris kept away from the water submersed electrode by means of a water andsalt impermeable dielectric coating. Thus, cheaper electrode materialscan be used, which is possible because an AC generator is used to powercapacitive coupled loads.

Hence, in another aspect of the present invention a system is presented,said system comprising a load arrangement as disclosed herein, animpressed current cathodic protection (ICCP) system and a control unitfor controlling said load arrangement and said ICPP system to work incombination. Such an ICPP system generally applies a DC potentialdirectly to the seawater in using a special material water submergedelectrode (resistive connection to the seawater). Its aim is to providecathodic protection of damaged and non-painted) regions of a marinestructure.

In a practical implementation of the proposed load arrangement the firstexternal electrically conductive element is water and the capacitor isarranged for electrical power transmission through water to form anelectrical path via the water between the AC power source and thecapacitor.

According to another embodiment the load arrangement further comprisesan electrically conductive current guidance member for being arrangedwithin or attached to the second external element and the load forlowering the resistance in the conductive path of the load arrangement.This current guidance member further supports the current path betweenthe AC power source, e.g. a second AC terminal thereof, and the load,e.g. a second load terminal. It guides the current between theseelements. It is preferably not in galvanic contact with the AC powersource and the load, but is configured to be arranged within said waterand/or attached to the load arrangement.

In particular applications the electrical power arrangement comprises aplurality of loads, whose first load terminals are coupled in parallelto a common first electrode or separate first electrodes and whosesecond load terminals are coupled in parallel to a common secondelectrode, separate second electrodes or the second external element.Thus, various options exist for coupling the loads together. Preferably,several loads share a common AC power source to reduce the number ofconnections between the AC power source and the loads.

For use in an implementation directed to counter bio-fouling, where thefirst external element may be a ship hull, the load preferably comprisesa light source, in particular an LED or an UV-LED (e.g. an UV-C LED).

Further, the load may comprise a diode bridge circuit, wherein the lightsource is coupled between the midpoints of the diode bridge circuit. Theload may thus be considered as being sub-divided into multiple sub-loadsby deploying e.g. four low-cost Schottky diodes as a Graetz bridge (orGraetz circuit), thereby providing a local DC power supply (e.g. servingone or more light sources). This local DC power source can also be usedto operate other polarity sensitive electronics or any other electroniccircuit that requires DC power, such as a fouling monitor sensor andcontroller IC(s) in an anti-fouling application.

In another embodiment the load comprises a first LED and a second LEDcoupled anti-parallel to each other. This further improves the operationof the LEDs by means of an AC power source (e.g. an oscillator).However, due to the higher costs of one UV-C LED compared to fourSchottky diodes the Graetz bridge is more cost effective in providingpower during the full AC cycle.

According to one aspect the present invention is directed to a marinestructure, such as a ship or boat or vessel, having an outer surfacecomprising a load arrangement as disclosed herein, wherein the loadarrangement is attached to the said outer surface. The marine structuremay comprise an energy source for providing the energy for powering theload of the load arrangement. Said energy source may be a generator, anengine, a battery, a chemical reactor (for generating energy by achemical reaction of a substance e.g. with water) or generally any kindof source that is able to provide sufficient electrical energy forpowering the load of the load arrangement. Said energy source may becoupled to, or comprise, or represent the AC power source.

In a further aspect the present invention relates to a method forinstalling a load arrangement as disclosed herein to an outer surface ofa marine structure, e.g. a ship hull.

In a still further aspect the present invention relates to the use of aload arrangement as disclosed herein for installation to an outersurface of a marine structure, in particular to counter bio-fouling ofthe outer surface, e.g. a ship hull.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from andelucidated with reference to the embodiment described hereinafter. Inthe following drawings

FIG. 1 shows a schematic diagram of a first embodiment of an electricalpower arrangement according to the present invention,

FIG. 2 shows a schematic diagram of the first embodiment of anelectrical power arrangement in an anti-fouling application scenario,

FIG. 3 shows a cross-sectional side view of a first embodiment of a loadarrangement according to the present invention,

FIG. 4 shows a schematic diagram of a second embodiment of an electricalpower arrangement according to the present invention,

FIG. 5 shows a schematic diagram of the second embodiment of anelectrical power arrangement in an anti-fouling application scenario,

FIG. 6 shows a schematic diagram of a third embodiment of an electricalpower arrangement according to the present invention,

FIG. 7 shows a schematic diagram of the third embodiment of anelectrical power arrangement in an anti-fouling application scenario,

FIG. 8 shows a schematic diagram of a fourth embodiment of an electricalpower arrangement according to the present invention in an anti-foulingapplication scenario,

FIG. 9 shows a schematic diagram of a fifth embodiment of an electricalpower arrangement according to the present invention in an anti-foulingapplication scenario,

FIG. 10 shows a schematic diagram of a sixth embodiment of an electricalpower arrangement according to the present invention,

FIG. 11 shows a schematic diagram of the sixth embodiment of anelectrical power arrangement in an anti-fouling application scenario,

FIG. 12 shows diagrams of a locally cut segmented second electrode andof a damaged segmented second electrode,

FIG. 13 shows a side view and a top view of a practical implementationof an electrical power arrangement according to the present invention inan anti-fouling application scenario,

FIG. 14 shows a side view of another practical implementation of anelectrical power arrangement according to the present invention in ananti-fouling application scenario, and

FIG. 15 shows examples of the combination of an active UV-C LED stripand an add-on passive UV-C light guide executed as a roll, tile orstrip.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the present invention will be explained with referenceto an application scenario, in which it is used for powering of UV lightsources (in particular LEDs), that may be mounted to the outer surfaceof a ship hull to counter bio-fouling. Hence, before the details ofvarious embodiments of disclosed subject matter will be explained, thegeneral idea and known approaches to counter bio-fouling in such anapplication scenario will be discussed.

WO 2014/188347 A1 discloses a method of anti-fouling of a surface whilesaid surface is at least partially submersed in a liquid environment.The disclosed method comprises providing an anti-fouling light,distributing at least part of the light through an optical mediumcomprising a silicone material and/or UV grade (fused) silica, andemitting the anti-fouling light from the optical medium and from thesurface. Such anti-fouling solutions are based on UV-C irradiation toprevent the (initial) settlement of micro- and macro organisms, forinstance on a ship hull. The problem with bio-films is that as theirthickness increases over time due to growth of the organisms its surfaceroughens. Hence, the drag increases, requiring the engine to consumemore fuel to maintain the ship's cruising speed, and thus theoperational costs increase. Another impact of bio-fouling can be areduction in the cooling capacity of a pipe radiator or a flow capacityreduction of salt water intake filters and pipes. Therefore, service andmaintenance costs increase.

A potential solution to counter bio-fouling of the ship hull can be thecoverage of the exterior hull with slabs of for example UV-C transparentmaterials having embedded UV-C LED(s). These slabs, or generally anyloads or load arrangement (i.e. elements or arrangements consumingelectrical energy), are located below the waterline. This is because thesubmerged surfaces are predominantly sensitive to bio-fouling and,hence, responsible for the increase in drag. Hence, electrical powerneeds to be delivered under the water-line towards the loads.

The combination of electricity, water and the rough and toughenvironment of the off-shore industry possess a real challenge. This isbecause (sea) water is a good electric conductor and, hence, shortcircuits may easily arise. Furthermore, water decomposes under theinfluence of an electrical current. In the case of sea water itdecomposes under DC current in chlorine and hydrogen gas. Under ACcurrent, both gasses are formed alternatingly at each electrode. Anadditional problem with the gasses formed is that chlorine can enhancethe already natural occurring corrosion of the steel ship hull andaccelerates the degradation of other materials including the UV-C LEDsif not hermetically sealed. The hydrogen gas on the other hand can causeiron embrittlement, eventually leading to severe crack formation withinthe iron bulk.

To counter natural corrosion of the steel hull most ships are coated orpainted and in addition often equipped with passive or active cathodicprotecting systems such that the ship hull remains protected againstnatural corrosion when the protective coat or paint fails locally.Passive systems use sacrificial Zinc, Aluminum or Iron anodes thatdissolve electro-chemically over time, whereas active systems impress aDC current in using anodes made of MMO-Ti (mix metal oxides coatedTitanium) or Pt/Ti (Platinum coated Titanium). For active systemsimpressing a DC current into the sea water careful monitoring isrequired as too large currents may dissolve the hull locally at enhancedrates. Obviously, anti-fouling solutions should not render the cathodicprotection system to fail. Hence, the ship's hull should act as theground terminal, the protective currents should be DC, and the sea watermay serve as a high conductivity medium closing the electric circuit.

Furthermore, ship hulls get (severely) damaged over life, for exampledue to natural wear, non-intentional collisions with float wood andother close or near to the surface floating objects, or they may sufferfrom more controlled impacts due to collisions with other ships, such astowboats or ships bound adjacent. It is therefore more than likely thatalso the anti-fouling loads get damaged over life as well as the powersupply lines. Moreover, both loads and supply lines may get severelydamaged and even get cut to yield open circuits wet by the conductivesea water. Hence, unwanted electro-chemistry may occur because ofexternal inflicted damage. For this reason, DC power sources should notbe used as the primary power source for powering the loads.

However, to operate the UV-C LEDs, DC currents are generally preferred.Hence, within the anti-fouling load, means and methods are required thatcan generate local DC currents when fed with AC power. More preferably,the DC current source is isolated from the steel hull (preferablyserving as ground terminal). Thus, although electro-chemistry may occurwhen DC power terminals become exposed, the electro-chemistry will beconfined to the area of exposure. Furthermore, the magnitude of theelectro-chemistry will depend on the amount of DC current that can flowlocally and the surface area of the electrodes exposed. Hence, there isalso a need to limit the DC current near to a value as required by theUV-C LEDs (typically tenths of milli-Amperes for small LEDs) and tolimit the surface area of the exposed local DC power terminals.

Hence, in practice a substantial area of the anti-fouling solution maybecome damaged over life. In theory, the damage can comprise localdamage of one or more UV-C LEDs within one or more loads or even a largepart of a load might disappear. Hence, (seamless) tiled loads areproposed in an embodiment. Within the tile some kind of sub-division ofthe UV-C LEDs and power source may be provided, since one failing LED(or, generally, load) should not yield the functional remainder of thetile to become non-operational on damage. Hereby, failing LEDs can yieldeither an open or a short circuit, and since UV-C LEDs are ratherexpensive, it is recommended to avoid series LED strings.

Obviously, also tiled loads will still require some kind of electricalpower, either wired or wireless. Given the expected issues with a wirehassle, the off-shore industry is rough and tough, wireless powersolutions are preferred and proposed by the present invention. Yet, withboth the sea water and the iron hull being good electrical conductors,the power transfer losses in inductive systems as well as (RF) wirelesssolutions can be quite large. Besides that, they can be rather bulky.Hence, an attractive solution to provide electric power makes use of ACcapacitive coupling.

Conventional capacitive (wireless) power transfer systems use one or two(long) supply wires driven by an AC oscillator. When the supply wiresare covered with a dielectric film, a receiving element having twopick-up electrodes can be placed on top anywhere along the wires andpower is transferred. Further, in known electrical power arrangement forpowering a load the transferred power may be reactance limited. Thesystem functions because of the well isolating properties of the ambientair. Thus, high voltage electric fields can be set-up between the twopassive ground electrodes of the receiving element. However, when theambient environment becomes conductive, as is the case for sea water,the transfer of power becomes also facilitated anywhere along the twowires by the well conducting ambient. Hence, it is very difficult totransfer any power at all towards the intended receiving element.

According to the present invention the use of a capacitive powertransfer has been modified and optimized for application e.g. inelectrical power arrangements for transferring power to light sourcesmounted to the part of a ship hull that is usually under water, i.e. ina wet, conductive and harsh ambient environment. Furthermore, theelectric circuit has been adapted for robustness against moderate andsevere impact as well as surface cutting damage at the various levels,such as for example UV-C LEDs developing one or more open orshort-circuit connections.

FIG. 1 shows a schematic diagram of a first embodiment of an electricalpower arrangement 100 according to the present invention for powering aload 2. The electrical power arrangement 100 comprises a firstembodiment of a load arrangement 300 according to the present invention.The load arrangement 300 comprises a load 2 having a first load terminal2 a and a second load terminal 2 b, a first electrode 3 (also calledactive electrode hereinafter) electrically connected to the load 2 and adielectric layer 4. The load 2, the first electrode 3 and the dielectriclayer 4 form a structure, which is configured for being arranged at afirst external electrically conductive element 5. Further, the firstelectrode 3 and the dielectric layer 4 are arranged to form, incombination with a first external electrically conductive element 5, acapacitor 6 for capacitive transmission of electrical power between thefirst electrode 3 and the first external element 5. The load 2 isfurther connected to a second electrode 7 electrically insulated fromthe first electrode 3.

In this context, it shall be noted that the load 2, the first electrode3 and the dielectric layer 4 preferably form a structure. It shall beunderstood that the structure may not only be formed from theseelements, but that additional elements may be provided to form thestructure. In some embodiments these elements themselves are configuredto form the structure (e.g. the load and the first electrode dielectriclayer may be embedded in dielectric material of the dielectric layerthus forming the structure). In other embodiments one or more additionalelements (e.g. a carrier, a substrate, an adhesive layer, etc.) areprovided to form the structure together with these three elements.

The electrical power arrangement 100 further comprises an AC powersource 1 (e.g. an oscillator) having a first AC terminal 1 a and asecond AC terminal 1 b. The first AC terminal 1 a is arranged for beingelectrically connected to the first external element 5, i.e. aftermounting and in use the first AC terminal 1 a and the first externalelement 5 are electrically connected. The second AC terminal 2 b and thesecond load terminal 1 b are electrically connected to a secondelectrode 7 (also called passive electrode hereinafter). Hence,electrical power can be transmitted via the capacitor 6 from the ACpower source 1 to the load. As first external element 5, elementsavailable in the environment or infrastructure may be used, such as ahull of a vehicle, an electrically conductive floor cover and wallcover, part of building, etc. may be used.

FIG. 2 shows a diagram of the first embodiment of an electrical powerarrangement 200 and a load arrangement 400 in an anti-foulingapplication scenario. In this embodiment, the load 20 is a UV-C LED andthe first external element 50 is a ship hull, which is (at least partly)electrically conductive (i.e. the complete ship hull, only the innersurface, only the outer surface or only certain areas of the ship hullmay be configured to be conductive or made from conductive material,e.g. a metal). The AC power source 1 is generally arranged on board ofthe ship. The first AC terminal 1 a contacts the conductive surface ofthe ship hull 5, and the second AC terminal 1 b is connected by aconnection wire 1 c through the ship hull 5 with the second electrode 7.The LED 20, the dielectric layer 4 and the first electrode 3 (optionallyalso the second electrode 7) are preferably carried by a carrier 80,which is arranged at the first external electrically conductive element(5, 50).

The load arrangement 400 is configured such that the electricalcomponents are protected against the water 10 (in particular sea water).Several of such load arrangements can be coupled in parallel to the ACpower source 1, i.e. the second electrodes (which may be separateelectrodes or a common large second electrode) of multiple loadarrangements can be coupled to the same AC power source 1 and the sameconnection wire 1 c. In this way the number of AC power sources andconnection wires can be kept small even if the number of loadarrangements is large.

FIG. 3 shows a cross-sectional side view of an embodiment of the loadarrangement 400. The carrier 80 may be a thin plate, a sheet orsubstrate, made e.g. of a material (preferably fulfilling the abovedescribed requirements) resistant against the environment in which it isused. Preferably, the carrier 80 is flexible to be able to arrange it todifferent elements 5, e.g. to curve surfaces like a ship hull. Thedielectric layer 4 is provided on top of the carrier 80, and the load 2is embedded into the dielectric layer 4. Further, the first electrode 3is provided embedded in the dielectric layer 4. The electric loadterminal 2 b can be embedded in, sit on top of or even stick out of thedielectric layer 4. The second electrode 7 is provided on top of thedielectric layer 4.

For enabling arrangement of the being arranged at the first externalelectrically conductive element 5, e.g. the ship hull 50, in a simplemanner, an adhesive material 90 may be provided on one surface 81 of thecarrier 80. The adhesive material 90 may further be covered a removablefilm 91 as protection of the adhesive material 81 before application ofthe carrier 80 to the element 5.

Instead of adhesives which have a chemical base for fixation, hot melt(thermoplastic material, rigid when cold, once heated for example viasteam, becomes a fluid locally for a short time and ensures theconnection) or mechanical anchoring (micro hooks of two materials thatengage during binding) or a combination of these can be used.

Further, the size and/or form of the carrier 80 may be made to match theform and/or size of an area of application. For instance, the loadarrangement may be configured as a kind of tile or sticker, which isdesigned to match the form and/or size of the element 5 or such thatseveral of such stickers or tiles can be combined (placed adjacent toeach other) to cover the desired area of the element 5 in an easymanner.

Preferably, the surface 82 of the carrier 80 and/or the outer surface 92of the load arrangement opposite to the surface 81 of the carriercovered with the adhesive material is covered with an adhesive material93, in particular for receiving a light guide or dithering surface onone of the surfaces.

The carrier 80 may further comprise an indicator 94 for installation ofthe load arrangement, in particular for indicating the installationposition and/or installation direction and/or overlap possibility. Suchan indicator may simply be a dotted line or a cutting line or anygraphic that shows how and where to apply the carrier to the element 5.

Multiple load arrangements may be provided as a roll so that single loadarrangements can be taken from said roll and applied as desired, or awhole sequence of load arrangements can be used and appliedsimultaneously.

FIG. 4 shows a schematic diagram of a second embodiment of an electricalpower arrangement 101 including a second embodiment of a loadarrangement 301 according to the present invention, and FIG. 5 shows aschematic diagram of said second embodiment of the electrical powerarrangement 201 including the second embodiment of the load arrangement401 in an anti-fouling application scenario. Different from the firstembodiment, the second embodiment does not make use of a secondelectrode, but the second AC terminal 1 b and the second load terminal 2b are electrically connected to a second external electricallyconductive element 11 insulated from the first external element 5, inparticular by wires 1 d and 2 d. In the application scenario depicted inFIG. 5 the second external element 11 is preferably the water 10, inparticular sea water, through which the current path is closed betweenthe second AC terminal 1 b and the second load terminal 2 b, which hasthe advantage that no extra wire electrode 7 is required as in the firstembodiment. The wires 1 d and 2 d just need to be guided into the water10. The load arrangement 301/401 is preferably configured in a modularway. Like in the first embodiment the load arrangement 301/401preferably comprises a carrier (not shown in FIGS. 4 and 5). As thecurrent is transmitted via water instead of wiring there will be ease ofinstallation, cost reduction and flexibility. Further, the modularityalso allows for freedom of placement.

FIG. 6 shows a schematic diagram of a third embodiment of an electricalpower arrangement 102 including a third embodiment of a load arrangement302 according to the present invention, and FIG. 7 shows a schematicdiagram of the third embodiment of the electrical power arrangement 202including the third embodiment of the load arrangement 402 in ananti-fouling application scenario. Compared to the second embodiment,the third embodiment additionally comprises an electrically conductivecurrent guidance member 12 arranged within or attached to the secondexternal element 11 and between the second AC terminal 1 b and thesecond load terminal 2 b, without having galvanic contact with them.This current guidance member 12 may e.g. be an extra electrode (e.g. aplate or wire) arranged within the water 10 to lower the impedance ofthe current path between the second AC terminal 1 b and the second loadterminal 2 b. Again, the load arrangement 302 is preferably configuredin a modular way. The guidance member 12 may also sit on top of themodular sticker assembly in the form of a wire or a loop, or it can evenbe an extension of the wire 2 d. Thus the distance between adjacentloops is made by local sea water bridges (alternating chain of guidancemembers and sea water bridges).

Further, for the wire 1 d a (often already existing) DC power line maybe used. Such a DC power line is generally arranged within or attachedto the second external element, i.e. is guided into the water, to reduceor avoid natural corrosion of the ship hull. This DC power line 1 d maythus be reused and electrically connected to the second AC terminal 1 bto impress the AC current in addition to the DC current. This avoids theneed of additional wires and of additional bores through the ship hull.

FIG. 8 shows a schematic diagram of a fourth embodiment of an electricalpower arrangement 203 including fourth embodiment of a load arrangement403 according to the present invention in an anti-fouling applicationscenario. Compared to the first embodiment the load 2 comprises twoanti-parallel coupled LEDs 20 a, 20 b coupled between the firstelectrode 3 and the second electrode 7. This provides that they arealternately emitting light in the respective half period of the ACcurrent wave.

FIG. 9 shows a schematic diagram of the fifth embodiment of anelectrical power arrangement 204 including fourth embodiment of a loadarrangement 404 according to the present invention in an anti-foulingapplication scenario. In this embodiment the load 2 comprises a diodebridge 23 (also called Graetz bridge or Graetz circuit) of four Schottkydiodes and an LED 24 coupled between the midpoints 23 a, 23 b of thediode bridge. The diode bridge 23 serves as rectifier for rectifying thecoupled AC current so that the LED 24 is illuminating in both halfperiods of the AC current.

FIG. 10 shows a schematic diagram of a sixth embodiment of an electricalpower arrangement 105 including a plurality of load arrangements 305 a,305 b, 305 c according to the present invention, and FIG. 11 shows aschematic diagram of the sixth embodiment of the electrical powerarrangement 205 in an anti-fouling application scenario comprising theplurality of load arrangements 405 a, 405 b, 405 c. The load 2 thuscomprises a plurality of loads 25 a, 25 b, 25 c (also called sub-loads),whose first load terminals are coupled in parallel to a common firstelectrode (not shown) or separate first electrodes 3 a, 3 b, 3 c andwhose second load terminals are coupled in parallel to a common secondelectrode 7 (as shown in FIG. 11), separate second electrodes 7 a, 7 b,7 c (i.e. a segmented second electrode as shown in FIG. 10) or thesecond external element (not shown). Each of the loads 25 a, 25 b, 25 cmay thereby be configured as shown in any one of FIGS. 1 to 9.

Unlike conventional solutions, the loads 25 a, 25 b, 25 c are connecteddirectly in parallel with the AC power source 1 and are terminated by apassive ground electrode (i.e. the second electrode(s) 7 or 7 a, 7 b, 7c), rather than using two active transfer electrodes in between the ACpower source 1 and the load 2. Also in this configuration the localcurrent is reactance limited by the surface area of the passiveelectrode, and, hence, the local DC current that can flow through, forexample, a short-circuit (LED).

For low resistivity electrodes, the effective current I is described byI_(subload)=U_(oscillator)*2*π*f*C, where U is the effective(oscillator) voltage and f the driving frequency. The value of the localcapacitance C depends on the local area of the segmented passiveelectrode 3 (or 3 a, 3 b, 3 c), the local thickness of the dielectriclayer 4 (or 4 a,4 b,4 c) in between the electrode 3 (or 3 a, 3 b, 3 c)and the common electrode 5 and the permittivity thereof. Since, thecurrent I depends on the applied drive voltage U, it may be understoodthat the power P transfer capability, even if the electrical powerarrangement is very efficient, is reactance limited, given byP_(eff)=U_(eff)*I_(eff). Thus to transfer a lot of power, high voltageand/or large capacitance is required. For the sake of safety it may beclear that large capacitance is preferred. Since ship hulls provide alarge surface area and UV-C LEDs are low-power, this can be usedaccording to the desired application scenario. Hence, also from theperspective of LED power it is beneficial to deploy a plurality of local(DC) power sources fed by a single (AC) supply line.

Beneficially, the dielectric material can be used to embed the LEDswithin a UV-C transparent, water and salt impermeable enclosure, i.e.all the elements may be accommodated within housing and can additionallyor alternatively be embedded in dielectric material, which may be thesame material as used for the dielectric layer 4. A suitable embeddingmaterial that is well UV-C transparent is silicone. In addition, sincethe area of the local passive electrode (the second electrode 7) and thelocal dielectric material thickness are design parameter, even LEDs andother electronics requiring different current and/or voltage levels canstill be connected to one and the same oscillator. Beneficially, the useof a single drive line reduces the problem of a wire hassle since anywire is allowed to be connected to any other wire. This eases theinstallation, in particular in the off-shore industry.

It can be deduced from the formula given above that the area of thepassive electrode can be minimized in deploying higher drivingfrequencies, thereby potentially limiting the area/volume of thevulnerable electronics. For a large effective sub-load current (i.e.current through one of a plurality of loads 25 a, 25 b, 25 c, as e.g.shown in FIGS. 10 and 11) to flow, however, the surface area of thepassive electrode will still have a certain size. Fortunately, it doesnot matter if the area becomes cut on damage, in that a cut will hardlyreduce its surface area. This is illustrated in FIG. 12A showing adiagram of a locally cut segmented second electrode 7 b as used in anembodiment of the electrical power arrangement, wherein the cuts 70 havehardly any impact on the effective passive electrode area.

Only if the surface area of the passive electrode is reduced, asillustrated in FIG. 12B showing a diagram of damaged segmented secondelectrodes 7 b, 7 c, the LED output of the LED in the sub-loads 25 b, 25c becomes reduced, which is undesired. Hence, for a substantiallydamaged passive electrode area, the area is affected significantly. Indeploying load share resistors, part of the area loss can be compensatedfor by the nearest neighbors, with the value of R determining how manyand to what extent (functional, open or short-circuit) neighbors cancompensate for the experienced area loss.

To cope with passive electrode damage, load share resistors 26 a, 26 bmay be deployed connecting one or more adjacent passive sub-electrodes 7a, 7 b, 7 c in parallel, as also illustrated in FIG. 12B. One benefit ofthe load-share resistors 26 a, 26 b is that in the undamaged casesignificant differences between adjacent sub-electrodes 7 a, 7 b, 7 c donot exist and, hence, there is hardly any power dissipation in the loadshare resistor 26 a, 26 b. When there is damage, part of the damaged LEDcurrent can be carried by the neighboring sub-electrodes 7 a, 7 b, 7 c.How much sharing is possible depends on the value of the load shareresistor 26 a, 26 b. For a low value of the load share resistor 26 a, 26b, a substantial fraction of passive electrode area is allowed to bemissing. However, if one or more of the neighbors also develop ashort-circuit, a too large short-circuit current can flow. When thevalue of the load share resistor 26 a, 26 b is too high, there is hardlyany missing electrode compensation possible. Hence, a fair load sharingcapacity of 10-40% is estimated to be a reasonable value. In the case ofa 20 mA UV-C LED current, load share resistor values of about 1-4 kΩ arereasonable, but the value is not limited to this range.

As discussed above, if the area of the local active electrode (i.e. thefirst electrode) is designed to allow for a maximum current with a valueequal or near to that of the UV-C LED, sub-loads are allowed to developa short-circuit without significantly affecting their functionalneighbors (with or without load share resistor). Consequently, in caseboth the positive and the negative terminal of a local DC power sourcebecome exposed upon damage, also the magnitude of the electro-chemicalcurrent is limited, whereas its location is confined to the area ofdamage. Since the exposed terminals will dissolve over time, the amountof electro-chemistry will also reduce over time if not stopped in fullbecause of material dissolution.

Satisfactory results may e.g. be obtained for drive frequencies rangingbetween 0.1 and 100 MHz. AC electro-chemistry takes place and corrosionwill form, for example when the supply wire 1 b is cut. Damage controlis therefore required. Here another benefit of a high oscillatorfrequency (>˜20 kHz) exists. If the supply wire 1 b (power supply wiresupplies AC power and hence induces AC electro-chemistry; within theload AC is converted to DC, and DC electrochemistry takes place, butonly locally) is exposed towards the sea water, the supply wire and thehull will act as alternatingly anode and cathode. For high frequenciesthis is not different, yet, for both electrodes the waste products ofthe electro-chemistry will be available at each electrode and instoichiometric amounts for a symmetric drive voltage. More importantly,due to formation kinetics of the gas bubbles, the bubbles will still besmall-sized before the polarity reverses. Hence, auto-ignition and thusself-annihilation takes place. This process generates heat, but theamount of free waste products is reduced dramatically.

Another benefit of the proposed solution is that the closing of theelectric circuit is done by means of the passive electrode area inseries with either the well conductive sea water below the water line ornon-conductive air above the water line. Hence, the loads above thewaterline self-dim. Besides the conductivity, also the dielectricconstants above and below the waterline are different with again theresulting effect working in the right direction. Loads above the waterline can thus be made to dim passively, depending on the coupling ratiotowards the ship hull and the ambient sea water/air, thereby savingenergy and, at the same time, reducing the amount of UV-C radiated intothe ambient environment above the water line. If required the LEDs caneven be turned off in full by deploying an active detection circuit.Different embodiments describe the different means and methods toachieve this (e.g. using different dielectric thicknesses, differentmaterials, two level passive electrodes, a detour hole toward the hullthat may wet or not, etc.).

According to one aspect of the present invention all loads are connectedin series with the oscillator (AC power source), terminated by a passiveground. An advantage of this setup is that all the current flowing fromthe passive electrode to ground also flows through the sum of sub-loads.The efficiency or power transfer of this setup is determined by theratio of the energy consumed by all the sub-loads and that dissipated(in series with the loads) by the ambient environment at the passiveground electrode. When the ambient environment is well conducting (lowseries resistivity), which is the case for sea water and the ship hull,the power losses are low. This is because the ship hull is thick, has alarge surface area and is made of well electrically well conductingsteel, whereas the resistive losses of the sea water are small becauseof its rather high conductivity. In fact, the ship hull is floating inan infinite, liquid array of 3D resistors. Moreover, all resistive pathsto ground are in parallel, yielding a very low effective resistance.Above all, this resistance is self-adapting in that the sea waterfollows the contours of the ship hull either in movement or stationaryas well as that it adapts to differences in the waterline due tovariations in load (cargo/ballast water or both). Thus, under allcircumstances the efficiency of the proposed electrical powerarrangement is high and optimal.

Given the expected low-loss contributions of the ship hull and seawater, the dielectric properties of the dielectric layer on top of thesegmented passive electrodes are, hence, most important. The lossrelated to this layer can be very low when for example silicone is used.The use of silicones is furthermore beneficial as it is UV-C transparentand water and salt blocking.

Another aspect of the present invention relates to the potential cuttingof the common power line (i.e. the supply wire 1 b) and subsequentexposure to the sea water. Although such cutting will render the loadsconnected down-stream to become inoperative, the amount of power dumpedinto the sea water and the time that such dumping takes place can beminimized. This can be done on optimizing its physical dimensions aswell as its rate of erosion on exposure. The common power line istherefore preferably executed as a thin and wide strip, rather thanexecuting it as a thick round wire. In addition, ductile materials maybe used, such as gold, silver, copper and aluminum that can be cut andtorn easily. Of these materials, aluminum is the most preferredmaterial, as aluminum will also dissolve in both acidic and basicenvironments. Thus, when electro-chemistry takes place aluminum willdissolve much faster than most other materials, while it is still a goodelectrical conductor. In addition, chlorine gas and ions both acceleratethe dissolution of aluminum already by nature. Hence, the surface areaof the exposed strip or cross-section will be reduced rapidly, therebyrapidly decreasing the amount of power dumped toward the ambient seawater.

Furthermore, aluminum has a low melting point, allowing for theintegration of one or more fuses into the power line itself.Beneficially, aluminum is also a very good reflector for UV-C. Thus,both power line and passive electrodes are preferably executed in(sheet) aluminum. Furthermore, aluminum allows for the (wire) bonding ofelectronic components without the need for solder, and it can be laserwelded. Hence, the full integration of all the electronic componentsinto an UV-C LED strip, also having passive segmented electrodes ispossible. In addition, LEDs strips can be easily adhered to curved andcontoured surfaces and can be made in long lengths. An LED strip or LEDsticker may hence be used in an embodiment. Furthermore, the thicknessof the sticker carrier can be easily controlled over large areas andlengths, and hence, the capacitance to the hull can be set with littleeffort (area of the electrodes 3 and 7 patterned directly on top of thecarrier.).

If an LED strip or LED sticker is used having only a single power supplywire, the remainder of the anti-fouling tile (i.e. of the loadarrangement) may comprise a “passive” tiling, comprising only an UV-Clight guide, optically connected to the LED strip. This can be a snapover tile (light guide goes over LED strip), or be a slab of lightguiding material filling the gap between adjacent LED strips, orcomprise a plurality of smaller tiles filling the space in between LEDstrips. The advantage is that the light guides can be cut to measure tofill the gap without damaging the LED strips. The optical couplingbetween the light guiding members and LED strips can be executed as air,(sea) water or silicone.

Generally, the connection wire 1 c may be directly (galvanically)connected to the second electrode 7 or may end in the water so that theconnection between the connection wire 1 c and the second electrode 7 ismade through the water, which is particularly useful In case of use asticker-type solution of the load arrangement. These different solutionsshall be indicated by the dotted line between the end of the connectionwire 3 and the second electrode 7 (particularly in FIGS. 8 and 9).Further, the second electrode 7 is preferably directly connected to theload 2, i.e. there is generally no (long) connection between the loadterminal 2 b and the second electrode 7.

In the following further embodiments will be described.

FIG. 13 shows a side view (FIG. 13A) and a top view (FIG. 13B) of apractical implementation of an electrical power arrangement 106according to the present invention in an anti-fouling applicationscenario, which is similar to the sixth embodiment depicted in FIGS. 10and 11. In this embodiment a single, thin and wide conductive powersupply wire 3 (representing the first electrode) carried on top of oneor more dielectric (adhesive) substrates 40 (part of which representingthe dielectric layer 4) is provided, with the single supply wire 3(being connect to the AC terminal 1 b directly or by external member 11(sea water)) preferably being executed in sheet aluminum and beingvoltage modulated by a high frequency AC oscillator (not shown). Thesingle supply wire 3 is galvanically connected to a plurality of loads25 a, 25 b, 25 c connected in parallel, including for example local DCpower sources executed in the form of a Graetz bridge 23 and LEDs 24 asshown in FIG. 9 or 12. Each load 25 a, 25 b, 25 c is terminated by acurrent limiting passive ground electrode 7 a, 7 b, 7 c.

Across the Graetz bridge 23 of every load 25 a, 25 b, 25 c there may beone or more electronic components connected, such as (UV-C) LEDs, ICsand/or other electronic circuits and modules. Preferably, the wholeassembly is enclosed in a UV-C transparent, water and salt impermeableenclosure 41, e.g. made of silicone.

The supply wire 3 (representing the first electrode) may be providedwith one or more integrated fuses 26 (e.g. executed in sheet aluminum)and a water tight, insulated attachment of the power supply wire. Thefuse provides safety in case of wire damage. This is illustrated in FIG.14 showing a top view of another practical implementation of anelectrical power arrangement 107 according to the present invention inan anti-fouling application scenario.

In another embodiment the passive electrode areas 7 a, 7 b, 7 c may alsobe executed in sheet aluminum. Further, the passive electrode areas maybe executed such that multiple capacitance values can be obtained,depending on the electric and dielectric properties of the ambientenvironment. For example, different thicknesses of the dielectric at thetop and the bottom side of the passive electrode, or two differentdielectric materials (e.g. one sticks well and the other having a betterUV transparency), or a locally thinned dielectric material on top inform of a hole that can be wet sea water, may be deployed. Anotherexample is a passive electrode split in two or more connected sub-parts,with one or more part raised in plane when compared to the other partclose to the carrier substrate. Further, the reverse of these optionsdescribed above may be used. Yet another embodiment may comprise aninflatable or flapping passive electrode or a cavity below or on top ofa passive electrode, allowing for local height and/or dielectricmaterial adjustment. These are just examples of options that can be usedto tune the individual contributions of the upper and low half of thepassive ground electrode with the aim to auto-dim the local LEDsdepending on the dielectric and electric properties of the ambientenvironment.

In still another embodiment the LED strip 25 a, 25 b may be opticallyextendable by an add-on light guide, for example executed as a roll 27a, a tile 27 b or any other shaped extendable, yet, passive UV-C lightguide as illustrated in FIG. 15. Such tiles can be damaged and/or loston impact and be replaced as easily as required.

In some or even all of the above explained embodiments, according to thepresent invention at least one of the capacitor 6 and the second loadterminal 2 b is arranged for electrical power transmission through water10, 11 to form an electrical path via the water 10, 11 between the ACpower source 1 and the respective one of the capacitor and the secondload terminal 2 b. Further, the first load terminal 2 a is electricallyinsulated from the second load terminal 2 b. Thus, the above explainedembodiments may be equally applicable, but with a modification of theelectrical path.

Hence, in some embodiments there is no galvanic connection presentbetween the second AC power terminal 1 b and the second load terminal,but the electrical path may be formed through the water 10, 11, whereina resistive or capacitive connection may be formed. Further, in someembodiments there is no galvanic connection present between the first ACpower terminal 1 a and the first external electrically conductiveelement 5, 50, e.g. the ship hull or the marine structure.

Other applications than the use at an external surface of a ship hullinclude buildings under water, such as a pier, pile of a bridge or windpower plant, etc.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive; theinvention is not limited to the disclosed embodiments. Other variationsto the disclosed embodiments can be understood and effected by thoseskilled in the art in practicing the claimed invention, from a study ofthe drawings, the disclosure, and the appended claims.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. A single element or other unit may fulfill the functions ofseveral items recited in the claims. The mere fact that certain measuresare recited in mutually different dependent claims does not indicatethat a combination of these measures cannot be used to advantage.

Any reference signs in the claims should not be construed as limitingthe scope.

It follows a list of further embodiments and aspects:

C1. A marine structure comprising:

a surface (50) and

a load (2, 20, 21, 22, 25) having a first load terminal (2 a) and asecond load terminal (2 b) for being powered by an AC power source (1),said AC power source (1) having a first AC terminal (1 a) electricallyconnectable to the surface (50) and a second AC terminal (1 b),

a first electrode (3) electrically connected to the first load terminal(2 a), and

a dielectric layer (4),

wherein the first electrode (3) and the dielectric layer (4) arearranged to form, in combination with the surface (50), a capacitor (6)for capacitive transmission of electrical power between the firstelectrode (3) and the surface (50),

wherein the second AC terminal (1 b) and the second load terminal (2 b)are arranged for being electrically connected to a second externalelectrically conductive element (10, 11) insulated from the surface(50), and

wherein the first load terminal (2 a) is electrically insulated from thesecond load terminal (2 b).

C2. The marine structure as defined in embodiment C1,

wherein the surface (50) is an external surface.

C3. The marine structure as defined in embodiment C2,

wherein the surface (50) is at least part of a ship hull.

C4. The marine structure as defined in embodiment C1,

further comprising an AC power source (1) for powering said load.

C5. The marine structure as defined in embodiment C1,

further comprising a carrier (80) carrying the load (2), the firstelectrode (3) and the dielectric layer (4) and being configured forbeing arranged at the ship hull (50).

C6. The marine structure as defined in embodiment C1,

further comprising a second electrode (7) electrically connected to theload (2) and being arranged for being electrically connected to an ACpower source (1).

C7. The marine structure as defined in embodiment C1,

wherein the load (2) is arranged for being electrically connected to thesecond external electrically conductive element (10, 11), which iswater, in particular sea water.

C8. The marine structure as defined in embodiment C1,

further comprising an electrically conductive current guidance member(12) arranged within or attached to the second external element (10, 11)and the load terminal (2).

C9. The marine structure as defined in embodiment C1,

further comprising a DC power line (1 d) arranged within or attached tothe second external element (10).

C10. The marine structure as defined in embodiment C1,

further comprising a housing (8) accommodating the load (2, 20, 21, 22),the first electrode (3) and the dielectric layer (4).

C11. The marine structure as defined in embodiment C1,

comprising a plurality of loads (25 a, 25 b, 25 c), whose first loadterminals are coupled in parallel to a common first electrode (3) orseparate first electrodes (3 a, 3 b, 3 c) and whose second loadterminals are coupled in parallel to a common second electrode (7),separate second electrodes (7 a, 7 b, 7 c) or the second externalelement (10, 11).C12. The marine structure as defined in embodiment C1,wherein the load (20, 21, 22) comprises a light source, in particular anLED or an UV-LED.C13. The marine structure as defined in embodiment C12,wherein the load (22) comprises a diode bridge circuit (23), wherein thelight source (24) is coupled between the midpoints (23 a, 23 b) of thediode bridge circuit (23).C14. The marine structure as defined in embodiment C1,wherein the load (21) comprises a first LED (21 a) and a second LED (21b) coupled anti-parallel to each other.C15. The marine structure as defined in embodiment C5,wherein the ship hull (50) is covered by a plurality of carriers (80)and wherein a plurality of AC power sources (1) are provided, each beingconfigured for powering the loads of two or more carriers (3).B1. A load arrangement for use in an electrical power arrangement andfor arrangement at a first external electrically conductive element (5,50), said load arrangement comprising:

a load (2),

a first electrode (3) electrically connected to the load (2), and

a dielectric layer (4),

wherein the load (2), the first electrode (3), the dielectric layer (4)form a structure, which is configured for being arranged at the firstexternal electrically conductive element (5, 50), wherein the firstelectrode (3) and the dielectric layer (4) are arranged to form, incombination with a first external electrically conductive element (5,50), a capacitor (6) for capacitive transmission of electrical powerbetween the first electrode (3) and the first external element (5, 50),andwherein the load (2) is connected to a second electrode (7) electricallyinsulated from the first electrode (3) or is arranged for beingelectrically connected to a second external electrically conductiveelement (10, 11) electrically insulated from the first electrode (3).B2. The load arrangement as defined in embodiment B1,further comprising a carrier (80) carrying the load (2), the firstelectrode (3) and the dielectric layer (4) and being configured forbeing arranged at the first external electrically conductive element (5,50).B3. The load arrangement as defined in embodiment B2,wherein the carrier (80) is in sheet form, wherein at least one surface(81) of the carrier is covered with an adhesive material (90).B4. The load arrangement as defined in embodiment B3,further comprising a film (91) removably attached to the surface (81)covered with the adhesive material (90).B5. The load arrangement as defined in embodiment B2,wherein the size and/or form of the carrier (80) is made to match theform and/or size of an area of application.B6. The load arrangement as defined in embodiment B3,wherein the surface (82) of the carrier (80) and/or the outer surface(92) of the load arrangement opposite to the surface (81) of the carriercovered with the adhesive material (90) is covered with an adhesivematerial (93), in particular for receiving a light guide or ditheringsurface on one of the surfaces.B7. The load arrangement as defined in embodiment B2,wherein the carrier (80) is made of flexible material.B8. The load arrangement as defined in embodiment B2,wherein the carrier (80) comprises an indicator (94) for installation ofthe load arrangement, in particular for indicating the installationposition and/or installation direction and/or overlap possibility and/oran indicator (94) indicating where to cut the carrier (80).B9. The load arrangement as defined in embodiment B1,further comprising a second electrode (7) electrically connected to theload (2) and being arranged for being electrically connected to an ACpower source (1).B10. The load arrangement as defined in embodiment B1,further comprising an electrically conductive current guidance member(12) for being arranged within or attached to the second externalelement (10, 11) and the load (2).B11. The load arrangement as defined in embodiment B1,further comprising a DC power line (1 d) for being arranged within orattached to the second external element (10).B12. The load arrangement as defined in embodiment B1,wherein the load (20, 21, 22) comprises a light source, in particular anLED or an UV-LED.B13. An electrical power arrangement for powering a load, saidelectrical power arrangement comprising:

an AC power source (1) and

a load arrangement as defined in any one of embodiments 1 to 12.

B14. A marine structure having an outer surface comprising a loadarrangement as defined in any one of embodiments 1 to 12, wherein theload arrangement is attached to the said outer surface.

B15. A method for driving a load arrangement as defined in any one ofembodiments B1 to B12 by providing an AC voltage between the firstexternal element (5, 50) and either the second electrode (7) or thesecond external electrically conductive element (10, 11).B16. A method for installing a load arrangement as defined in any one ofembodiments 1 to 12 to an outer surface of a marine structure.B17. Use of a load arrangement as defined in any one of embodiments 1 to12 for installation to an outer surface of a marine structure, inparticular to counter bio-fouling of the outer surface.

The invention claimed is:
 1. A load arrangement in an electrical powerarrangement comprising: a load, the load comprising a light sourceand/or a sensor and/or an electronic circuit, wherein the load has afirst load terminal and a second load terminal, and wherein the firstload terminal and the second load terminal are arranged to draw powerfrom an AC power source, a first electrode electrically connected to thefirst load terminal; and a dielectric layer, wherein the first electrodeand the dielectric layer are arranged to form, in combination with afirst external electrically conductive element, a capacitor, wherein thefirst external electrically conductive element is an outer surface of amarine structure, wherein the capacitor is arranged to capacitivelytransmit electrical power between the first electrode and the firstexternal electrically conductive element, wherein the capacitor and thesecond load terminal are arranged for electrical power transmission viawater between the AC power source and the capacitor, and wherein thefirst load terminal is electrically insulated from the second loadterminal.
 2. The load arrangement as claimed in claim 1, wherein thefirst external electrically conductive element is selected from thegroup consisting of water, sea water, an environmental object, a part ofa building a part of a vehicle, and an infrastructural object.
 3. Theload arrangement as claimed in claim 1, wherein the second load terminalhas an electrical connection via the water between the AC power sourceand the second load terminal, wherein the AC power source is attached tothe marine structure and the AC power source has an electricalconnection via the water between the AC power source and the second loadterminal.
 4. The load arrangement as claimed in claim 3, wherein thesecond load terminal and the AC power source have a capacitiveelectrical connection to the water or a resistive electrical connectionto the water.
 5. The load arrangement as claimed in claim 3, and whereinthe first external electrically conductive element is a ship hull or anelectrode, wherein the electrode is embedded or connected to anon-conductive marine structure.
 6. The load arrangement as claimed inclaim 1, further comprising an electrically conductive current guidancemember, wherein the electrically conductive current guidance member isarranged within or attached to the first external element, and whereinthe load for lowering the resistance is in the conductive path of theload arrangement.
 7. The load arrangement as claimed in claim 6, whereinthe guidance member is arranged within the water.
 8. The loadarrangement as claimed in claim 6, wherein the guidance member isattached to the load arrangement.
 9. The load arrangement as claimed inclaim 1, further comprising a plurality of loads, wherein each of theloads have a first load terminal and a second load terminal, whereineach of the first load terminals are coupled in parallel to a commonfirst electrode or separate first electrodes, and wherein each of thesecond load terminals are coupled in parallel to a common secondelectrode, separate second electrodes or the water.
 10. The loadarrangement as claimed in claim 1, wherein the load comprises a lightsource, wherein the light source is a diode bridge circuit, wherein atleast one of the diodes of the diode bridge circuit is an LED, andwherein the light source is coupled between the midpoints of the diodebridge circuit.
 11. An electrical power arrangement for powering a load,the electrical power arrangement comprising: an AC power source; and aload arrangement as claimed in claim
 1. 12. A system comprising: a loadarrangement as claimed in claim 1; an impressed current cathodicprotection system, and a control unit for controlling the loadarrangement and the impressed current cathodic protection system to workin combination.
 13. The load arrangement as claimed in claim 1, whereinthe load comprises a light source, wherein the light source is a LED.14. The load arrangement as claimed in claim 1, wherein the loadcomprises a light source, wherein the light source is a UV-LED.
 15. Theload arrangement as claimed in claim 1, wherein the load comprises alight source, wherein the light source is a first LED and a second LEDcoupled anti-parallel to each other.
 16. A load arrangement in anelectrical power arrangement comprising: a load, the load comprising alight source and/or a sensor and/or an electronic circuit, wherein theload has a first load terminal and a second load terminal, and whereinthe first load terminal and the second load terminal are arranged todraw power from an AC power source, a first electrode electricallyconnected to the first load terminal; and a dielectric layer, whereinthe first electrode and the dielectric layer are arranged to form, incombination with a first external electrically conductive element acapacitor, wherein the first external electrically conductive element isan outer surface of a marine structure, wherein the capacitor isarranged to capacitively transmit electrical power between the firstelectrode and the first external electrically conductive element,wherein the second load terminal is arranged for electrical powertransmission through water to form an electrical path via the waterbetween the AC power source and the second load terminal, and whereinthe first load terminal is electrically insulated from the second loadterminal.
 17. A load arrangement in an electrical power arrangementcomprising: a load, the load comprising a light source and/or a sensorand/or an electronic circuit, wherein the load has a first load terminaland a second load terminal, wherein the first load terminal and thesecond load terminal are arranged to draw power from an AC power source,a first electrode electrically connected to the first load terminal; anda dielectric layer, wherein the first electrode and the dielectric layerare arranged to form, in combination with a first external electricallyconductive element a capacitor, wherein the first external electricallyconductive element is water, wherein the capacitor is arranged tocapacitively transmit electrical power between the first electrode andthe first external electrically conductive element, wherein the firstload terminal is electrically insulated from the second load terminal,and wherein the capacitor is arranged for electrical power transmissionvia the water between the AC power source and the capacitor.